Accesing colors of a tex2D sample using range from 0-255 instead of 0-1

Unity Engine
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1

I want to get the color of a pixel of a texture in a shader.

This is my first time using shaders, i have seen some tutorials to understand abit of the shading lenguaje in unity.

Basically the idea would be;

  • Accessing a texture in the shader

  • Check the color of the texture at a pixel as if it was a Color32 in c# instead of a float4, something like;

if(col == (125,55,35,255))
{
   //do something
}

i have tried

fixed4 frag (v2f i) : SV_Target
{
      
 fixed4 col2 = tex2D(_MainTex, i.uv);

 if(col2.r == .6)
 {
     col2.g = .1;
 }

 return col2
}

So this will change the color, but i don’t want to check a float but the color as if it was a Color32(range from 0-255 instead of 0-1), since i can easily check the color value (for example 125,55,35,255 in that specific pixel) i have in a predetermined texture in a program like aseprite, to use as a some sort of color coded texture to do something when i’m checking a specific color in that texture.

I appreciate any suggestions since i have no idea how shaders work.